This invention relates to sleeves useful on surgical instruments. More particularly, it relates to such sleeves which provide a path for fluid, such as irrigation fluid, to the eye during eye surgery.
Sleeves are currently used in conjunction with surgical instruments, such as vitrectomy cutters, irrigation/aspiration instruments, emulsification instruments and the like, for example, to provide fluid to the eye, e.g., for irrigation and/or other purposes, while the eye is being surgically treated. Often, these sleeves are made of metal, such as stainless steel, in combination with silicone seals and tubes to connect irrigation infusion lines which support a fluidic-path to the eye during surgery. However, such metal sleeves must be very precisely and carefully made, for example, in order to avoid having the fluid leak from the fluidic path. If effective seals are not provided, fluid will leak proximally of the sleeve and/or through the opening through which the distal end portion of the instrument extends out of the sleeve. If the sleeve is made of metal, it must be precision machined to effect the desired fluid seals. In certain instances, the metal sleeve is custom built for one particular instrument so that the fluid seals are effective. Thus, the metal sleeves are expensive and difficult to produce, and may be useful with only one instrument, i.e., are often not interchangeable from instrument to instrument.
One alternative to metal which has been proposed is to make the sleeve out of a silicone polymer. Such silicone sleeves do often provide effective fluid seals. However, such sleeves, because of the softness of the silicone polymer, tend to collapse around the instrument, thus partially or completely blocking or obstructing the fluid flow path through the sleeve. This, in turn, is very disruptive to the surgical procedure and may be dangerous to the eyesight of the patient being treated. Also, such silicone sleeves are often tacky and can disadvantageously hang up or stick on the edge of the surgical incision.
Blake U.S. Pat. No. 4,573,979 discloses an irrigation/aspiration device which includes a cannula made of a stiff material such as metal or hard plastic, and a flexible support made of silicone rubber. This patent discloses a system in which the relative stiffness of the cannula is at least 10 or 100 times the stiffness of the flexible support. Moreover, the patent is not primarily concerned with organic polymeric materials and, in fact, discloses a preference for metal cannulas and silicone rubber supports.
Clearly, it would be advantageous to provide a sleeve which is easy and relatively inexpensive to manufacture, is disposable, provides effective fluid seals and is able to maintain an open fluid path during surgery.